From HERE
Theory One: It's short for "girdle string."
The first known reference to the item was found in J.H. Beadles' Western Wilds penned in 1878. "Around each boy's waist is the tight 'geestring,' from
which a single strip of cloth runs between the limbs from front to back." Back in the day, a girdle pretty much fit the above description.
Theory Two: It's a reference to a fiddle.
Musically speaking, a G-string is the lowest, darkest string on a violin. The emphasis on this theory is on the word "low" -- low note, low-cut
underwear.
Theory Three: It comes from a Native American word.
Many etymologists believe that it originated from the native word "geestringi." Apparently this was an item of clothing worn by some Plains Indians.
The word was changed to the more English sounding "G-string." |